Aromatic and aliphatic diamines and alkyl substituted derivatives thereof have been utilized as chain extenders in preparing polyurethanes as well as curatives for epoxy resins. To enhance light stability, the corresponding cyclohexylamine derivatives have been utilized. A variety of substituent groups have been incorporated into the aromatic and cyclohexylamines to alter the reactivity of the amine group for the function intended. Representative patents which show various aromatic diamines and cyclohexyl derivatives thereof for use as intermediates in preparing organic commodities such as polyurethanes and polyepoxide resins are as follows:
German Pat. No. 907,294 discloses the production of 4,4'-diaminodicyclohexyl methanes by hydrogenating 4,4'-diaminodiphenylmethane with hydrogen at high temperatures. Specific derivatives include the 4,4'-diamino-3,3'-dimethyldiphenylmethane; 4,4'-diamino-3,3',5,5'-tetramethyldicyclohexylmethane and 4,4'-diamino-2,2',5,5'-tetramethyldicyclohexylmethane. The compositions are allegedly suited as intermediates for dyes, polymers and textile processing aides.
U.S. Pat. No. 4,324,867 discloses reactive aromatic diamines for preparing polyurethane-polyurea elastomers and are represented by the formula: ##STR2## wherein the R groups are hydrogen or an alkyl radical having from 1 to 4 carbon atoms. Representative named diamines include 3,3'-ditertiarybutyl 4,4'-diaminophenylmethane; 3,3'-diethyl-5,5'-diisobutyl-4,4'-diaminophenylmethane; 3,3',5,5'-tetratertbutyl-4,4'-diaminophenylmethane and 3,3'-dimethyl-5,5'-ditertiarybutyl-4,4'-diaminophenylmethane.
U.S. Pat. No. 3,629,181 discloses various cycloaliphatic diamines as curing agents for poly epoxide resins and the diamines include 4,4'-diaminodicyclohexylmethane; 4,4'-methylene-bis-(2-methyl-cyclohexylamine) and others.
U.S. Pat. No. 3,351,610 discloses various epoxy resins compositions utilizing a ditertiary cycloaliphatic amines as the curing agent. Examples include 2,2-bis-(4-dimethylaminocyclohexyl)propane and 4,4'-di-(dimethylamino)-3,3',5,5'-tetramethyldicyclohexylmethane and so forth.
U.S. Pat. No. 3,321,438 discloses various polyamines suited as curing agent for polyepoxide resins. Representative diamines include di(3-methyl-4-amino cyclohexyl)methane and di(4-aminocyclohexyl)methane.